Hydrocarbonaceous condensation products



United States Patent 3,243,424 HYDRDCARBONACEOUS CONDENSATION PRODUCTSFranklin I. L. Lawrence and Michael J. Pohorilla, Bradford, Pm,assignors to Kendall Refining Co., a corporation of Pennsylvania NoDrawing. Original application Oct. 12, 1955, Ser. No. 540,159. Dividedand this application Nov. 26, 1962, Ser. No. 250,454

2 Claims. (Cl. 260-139} This is a division application of my copendingapplication Serial No. 540,159, filed October 12, 1955.

This invention relates to the improvement of the viscosity index,detergency, and depression of the pour point of oleaginous compositionsincluding lubricating oils, greases, power transmission fluids, andshock absorber fluids, which are characterized by a boiling point inexcess of 400 F. and a flash point in excess of 200 F. Moreparticularly, the invention embraces lubricating oils, greases, powertransmission fluids, and shock absorber fluids, of the aforementionedtype, which contain viscosity index improving amounts of substantiallyoil compatible hydrocarbonaceous condensation products formed bycontacting a hydrocarbon starting material having a molecular weight inexcess of about 500 while at a temperature of at least about 400 F., forexample, about 400 F. to about 600 F., with a free oxygen-containinggas.

The wide use of automobiles, aircraft, and other types of machines andapparatus, which are operated through a widely varying temperatureranges requires lubricating oils, greases, power transmission fluids,and shock absorber fluids which have a boiling point in excess of 400 F.and a flash point in excess of 200 F., and which are further attended bysuperior viscosity-temperature characteristics. Materials known to theart to have the racers sary boiling and flash points, such as mineraloil fractions, demonstrate excessive variations in viscosity withtemperature. Ideally, the viscosity of lubricating oils, powertransmission fluids, and shock absorber fluids, would be substantialiyconstant throughout wide ranges of temperature. The art has, therefore,sought to combine appropriate additives with lubricating oils, greases,power transmission fluids, and shock absorber fluids, to improve theviscosity index thereof.

It is a primary object of this invention to provide compoundedlubricating oils, greases, power transmission fluids, and shock absorberfluids of improved viscosity index.

It is an additional object of the invention to provide compositionseffective as viscosity index improving agents and detergents foroleaginous compositions, such as lubricating oils, greases, powertransmission fluids, and the like, which are resistant to oxidation.

It is yet another object of the invention to provide lubricating oils,greases, power transmission fluids, and shock absorber fluids which arecompounded with additive materials effective to simultaneously improvethe viscosity index and depress the pour point thereof.

In accordance with this invention, there are provided compoundedoleaginous compositions including lubricating oils, greases, powertransmission fluids, and shock absorber fluids having a boiling point inexcess of 400 F. and a flash point in excess of 200 F. containing aviscosity index improving amount of a substantially oil compatiblehydrocarbonaceous condensation product having a combined oxygen contentnot in excess of about 5% by weight, said condensation product beingproduced by contacting a hydrocarbon starting material having amolecular weight in excess of about 500, while at a temperature of atleast about 400 F., preferably about 425 F., to 575 F., with a freeoxygen-containing gas, for a Patented Mar. 29, 1966 time periodrequisite to produce a final product effective in a concentration ofabout 10% by weight to increase the viscosity index of a 60 at SUSstandard base mineral oil derived from a paraffinic crude source atleast 10 viscosity index units more than a like amount of thehydrocarbon starting material from which said condensation product isformed.

The viscosity index improving agents of this invention are usuallycharacterized by a ring and ball softening point, as measured byA.S.T.M. method E 28-421", of more than about 80 F. Some viscosity indeximproving agents comprehended by the invention have a ring and ballsoftening point or viscosity too low to be effectively measured inaccordance with the aforementioned procedure. Such materials arecharacterized by a viscosity of at least about 700 SUS at 210 F.,preferably at least about 2000 to 5000 SUS at 210 F. and, in any event,a viscosity of at least about 500 SUS at 210 F. greater than thehydrocarbon starting materials from which the viscosity index improvingagents are produced.

The substantially oil compatible hydrocarbonaceous condensation productswhich constitute the viscosity index improving agents of this inventionappear to result from the chain reaction of free radical intermediateswhich are formed thermally or by the reaction of at least some of themolecules of the hydrocarbon starting materials with oxygen. The highmolecular weight condensation products which are contemplated asviscosity index improvers by the invention contain a small amount, notin excess of 5% by weight of chemically combined oxygen and, therefore,are different in kind from products such as those resulting from therelatively low temperature air oxidation of paraffin waxes which, as theart has recognized, are essentially highly oxygenated compounds,generally of relatively low molecular weight, such as carboxylic acids,hydroxycarboxylic acids, lactones, ketones, and the like.

Any free oxygen-containing gas can be employed in the production of theviscosity index improving agents of the invention. Air is preferred.Substantially pure gaseous oxygen can be employed. Gaseous oxygen incombination with diluents inert under the conditions, such as nitrogen,carbon dioxide, and the like, can be employed.

The rate of supply of free oxygen-containing gas to the reaction mixtureis not critical to the production of the viscosity index improvingagents of the invention. Generally, the free oxygen-containing gas ispassed through the condensation reaction mixture at a rate requisite toprovide at least about 10 cubic feet of free oxygen per gallon ofhydrocarbon starting material per hour. Preferably, the freeoxygen-containing gas is supplied to the reaction mixture at a rate offrom about 11 to 27 cubic feet per hour per gallon of hydrocarbonstarting material. The corresponding air rates are at least about 50cubic feet of air per hour per gallon of hydrocarbon starting material,the preferred range being from about 55 to about cubic feet per hour pergallon of hydroeabron starting material. Reactive materials, such aschlorine, hydrogen chloride, phosphorus pentoxide, and like materials,which serve as activators can appropriately be introduced into thereaction mixture in conjunction with the free oxygencontaining gas.Conventional catalysts known to the art, such as the metal naphthenates,including cobalt naphthenate, can be employed, if desired.

The reaction time alone is not a critical aspect of the process for theproduction of the viscosity index improvers of the invention, thecondensation process being continued for a time period requisite toproduce a product having the previously defined characteristics. In sometypes of equipment, the process is completed in about 5 to 15 hours. Inother types of equipment, and with variations in starting materials, 10days or more may be required. The required reaction time is a functionof the temperature at which the condensation process is effected, therate of supply of free gaseous oxygen to the reaction mixture, and therate at which the heat of reaction is dissipated.

The hydrocarbon starting materials which are employed in the productionof the viscosity index improving agents of the invention must becharacterized by an average ebullioscopic molecular weight of at leastabout 500, preferably at least about 1000. An optimum averageebullioscopic molecular weight range is from about 1200 to 1700.

The most appropriate starting materials for the production of theviscosity index improving agents contemplated by the invention take theform of suitable fractions of crude oils. Appropriate fractions derivedfrom crude oils of any source, including Pennsylvania crude oils, Mid-Continent crude oils, West Coast crude oils, Canadian crude oils, andthe like, can be employed. All types of crude oils, including paraffinbase crude oils, asphalt base crude oils, and naphthenic crude oilsprovide suitable sources from which petroleum fractions useful in theproduction of the viscosity index improving agents of the invention canbe derived.

While the invention contemplates the production of viscosity indeximproving agents from pure or substantially pure individualhydrocarbons, such materials do not constitute optimum startingmaterials. It will be appreciated, however, that such pure hydrocarbonsof appropriate molecular weight can be suitably employed.

With respect particularly to fractions derived from Pennsylvania crudeoils, it is preferred that the hydrocarbon starting materials from whichthe viscosity index improving agents of this invention are produced becharacterized by a bromine number not in excess of 10.

It is additionally preferred that hydrocarbons which are utilized asstarting materials for the production of the viscosity index improvingagents of the invention contain more than about 2 naphthenic rings permolecule, which rings can be individually integrated with the paraffinicchain portion of the hydrocarbon molecules or condensed with aromaticrings and/or with other naphthenic ring systems. It is also preferredthat the hydrocarbon starting materials contain an average of not morethan about 50% aromatic carbons per molecule. Hydrocarbons which containan appreciable quantity of highly condensed ring systems, such as thosehydrocarbons which are found in the phenol or furfural extracts oflubricating oils, are operable and are most appropriately employed asstarting materials for the production of viscosity index improvingagents for synthetic lubricating oil compositions such as the diesteroils.

Additionally, it is preferred that the petroleum fractions from whichthe viscosity index improving agents of the invention are producedcontain not more than about 10% of wax type materials. The wax contentherein referred to is determinable by a procedure similar to thatdescribed under A.S.T.M. designation D72l5lT with the exception thatmethyl isobutyl ketone is employed to precipitate the wax, the samplesize is reduced to 0.5 gram, and the determination is conducted at F.While the starting materials which contain substantially more than byweight of wax, as determined by this test, e.g., petrolatum which mayreflect a Wax content on the order of 40% by weight, can be employed inthe production of the viscosity index improving agents of the invention,such materials are not preferred. Such materials can be best used byblending with more desirable starting materials, such as the preferredpetroleum fractions above described, in proportions up to about byweight of the total blend.

Normal or vacuum distillation residual stocks and analogous fractions ofparaflin base crude oils, such as Pennsylvania crude oils, are highlyappropriate starting materials for the production of the viscosity indeximproving agents employed in this invention. Hydrocarbons precipitatedby conventional propane precipitation 4 processes from such residualstocks are particularly suitable.

Further refinement of such propane precipitated, high molecular weighthydrocarbons, which include both light and heavy resin fractions, byextraction with furfural or phenol in conventional manner, yields araffinate from which viscosity index improving agents of maximumeffectiveness are produced. Conventional solvent extraction processesare utilized to obtain such rafiinates. Such processes are well known tothe prior art and are described in detail, inter alia, in Industrial andEngineering Chemistry, 40, pages 220-227 (1948), and at pages 335- 336of Chemical Refining of Petroleum by V. A. Kali chevsky and B. A.Stagner, Reinhold Publishing Co., 1942. Generally, the degree ofextraction should be such as to yield about a 70% to raflinate. Moredrastic extraction, for example, to yield 50% to 60% raflinates, may bepracticed to obtain still more desirable starting materials for theproduction of the viscosity index improving agents of the invention.

The most preferred starting material for the production of the viscosityindex improving agents of this invention embraces a solvent extractedPennsylvania crude oil fraction having a molecular weight of from about1200 to about 1700, a bromine number of not more than about 4, which issubstantially wax and asphalt free, which contains not more than about5% by weight of hydrocarbon molecules containing more than 5 aromaticrings, and which consists primarily of hydrocarbon molecules containingan average of from about 2 to about 7 naphthenic rings.

In some environments, it may be desired to protect the viscosity indeximproving agents of this invention against oxidation. In accordance withone feature of this invention, such protection is effected throughchemical modification of the hydrocarbonaceous condensation products,heretofore described, to produce non-equivalent materials. Morespecifically, the oxidation resistance of such condensation products isincreased by further chemical treatment to neutralize reactive groupsand/or simultaneously build antioxidant properties into the molecularstructure. Appropriate inorganic reagents for this purpose include P 5and elemental sulfur, which function to incorporate phosphorus, sulfur,or a combination thereof, in the condensation products. Further, partialreaction of such condensation products with sulfur followed by reactionwith aromatic amines and diamines, such as diphenylamine,o-phenylencdiamine, B-naphthylphenylamine, and the like, has been shownto reduce oxidation susceptibility of the viscosity index improvingagents of this invention.

Also, ammonia and polyalkylene polyamines derived from ethylene diamine,such as diethylene triamine, tricthylene tetramine, tetraethylenepentamine, and the like, or mixtures thereof, are also suitablemodification agents for the otherwise unmodified hydrocarbonaceouscondensation products of the invention.

Additionally, the various isocyanates which respond to the followingformula:

in which R is an alkyl group containing from 1 to 10 carbon atoms, and nis any integer from 1 to 3 inclusive, can be employed to modify theoxygen condensation products of the invention. Typical alkyl groupswhich are represented by R include methyl, ethyl, propyl, isopropyl,butyl, isobutyl, hexyl, octyl, decyl, and the like. R may also be aryl,including tolyl, phenyl, diphenyl methane, alpha-naphthyl, and the like,in the foregoing isocyanate formulae.

As illustrated in the ensuing examples, the aforementioned inorganic andorganic reagents are utilized, alone or in combination, by heating amixture of the condensation product and the selected reagent or reagentsat an appropriate temperature for a short period of time. In general, atleast about 0.25% by weight, preferably about 0.25% to about 5.0% byweight of the organic or inorganic reagents, or mixtures thereof. areemployed, based on the weight of the condensation product. Suchquanlilies generally afford an excess of the reagent, which is notobjectionable. The time and temperature of the reaction is not critical.the chemical routineer having requisite skill to carry out the process.in general, a temperature of from about I75 F. to about 500' F. and areaction time of at least about minutes, preferably from about 20 to I20minutes, can be observed with satisfactory results. in the case ofcertain of the organic reagents, temperatures must be controlled toprevent decomposition. A preferred procedure is to convert by blowingthe hydrocarbon fraction to a condensation product having a ring andball softening point somewhat below. for example. ft) to 20 below thesoftening point desired in the final product, followed by reaction withthe above described reagents to an extent requisite to raise the ringand ball softening point to the ultimately desired value.

Inasmuch as many condensation products are readily workable only atrelatively high temperatures. i.e., 350 to 450' F.. an alternativemethod for modifying such products is advantageously employed whenreagents are utilized which may be unstable at such high temperatures.Such alternative procedure embraces first blending the condensationproduct which is to be modified with the base stock in which it is to beultimately utilized in appropriate proportions followed by the additionof a suitable quantity of reagent. More specifically, the condensationproducts may be mixed in proportions from about 20% to 50% by weightwith the ultimate base stock in which they are to be utilized. To themixture so obtained. there is then added from about 1 to about 5% byweight of the desired reagents, based upon the condensation product,preferably in small proportions, under an atmosphere of nitrogen. Thedesired reaction is then effected at a temperature of from about 175' F.to 275' F. The ultimate product so obtained is then admixed inappropriate concentration with additional quantities of the base stockemployed. This procedure is particularly applicable in the modificationof the condensation product useful as a viscosity index improver throughutilization of such reagents as 8, and the isocyanates. as abovedefined.

Alternatively. the viscosity index improving agents of this inventionand fluids containing such agents, may be inhibited against oxidation byincorporation thercinto of various antioxidant materials,. includingthose ltnown to the prior art.

it has been discovered that the compositions of this invcntinttconstitute an excellent medium for blending with lubricating oils.various antioxidant and other materials which are insoluble in oilsalone and which, therefore, have heretofore been considered unsuitablefor use in lubricating oil compositions. Typical of such antioxidants isphenothialinc. and the substituted phenothiazines responding to thefollowing formula:

(in ,s

N. 'i If R, and R, are hydrogen or allzyl groups containing not morethan l0 carbon atoms including, by way of example, those variousspecific alkyl grou s specified with respect to Formula I. There can befrom 0 to 4 such R substitucnts in each aromatic nucleus.

Pursuant to this aspect of the invention, the condensation productsformed by contacting the hydrocarbon starting materials with a freeoxygen-containing gas are first heated to above the softening point andthe phenotltiazine or other antioxidant or material to be incorpot'atcdis then blended therewith. The blend so formed is thereafter dissolvedor dispersed in a lubricating oil, power transmission fluid. or thelike, in conventional manner. Antioxidants, other than phcnothiazines,which can be similarly employed. include ascorbic acid, low molecularweight dithiophosphate esters. such as the zinc dithiophosphates ofwhich the zinc salt of ethyl dithiophosphoric acid is represeptative,aromatic amines, such as p-naphthylphenylamine, di-p-naphthyl amine, andthe like Also, there may be blended with the oils, power transmissionfluids, and the like, containing the viscosity index improving and pourpoint depressing agents of this invention, antioxidants known to beuseful in lubricating oil. Typical of such antioxidants are the variousphenates. dithiophosphates, amines, phenols. dithiocarbamates,phosphites, and the like. It is the intent of this disclosure to embracesuch antioxidants generically. Since these materials are well known tothe art, they will not be further enumerated here.

Additional materials which can be incorporated into lubricatingcompositions through the medium of the viscosity index improving agentsof this invention include alkaline eat1h carbonates. such as those ofbarium and calcium, the various alkaline earth oxides and hydroxides,boric acid, boric acid esters, and the like.

It will be appreciated that the condensation products disclosed as beinguseful as viscosity index improving agents in this'invcntion can beemployed in fuel oil materials to prevent the precipitation of solidstherefrom as a result of the capability of such condensation products tosuspend finely divided solids. A typical example is a blend of virgindistillate gas oil and catalytically cracltcd fuel oil with 0.1% byweight of the viscosity index improving agent of Example I of thisspecification.

The viscosity index improving agents contemplated by this invention canbe opcrably employed in wide and effective proportions in all types ofmineral oils, greases. power transmission fluids, shock absorber fluids,and like materials, which are characterized by a boiling point in excessof 400 F. Specifically with respect to lubricating oils and greases, theviscosity index improving agents of the invention are appropriatclyutilized in a concentration of at least about l.0% by weight preferablyfrom about 3.0% to about 15.0% by weight.

The invention contemplates the use of the viscosity index improvingagents in all proportions effective to im prove the viscosity of alloleaginous compositions having a boiling point in excess of 400' F. anda flash point in excess of 200' F. including base oils, greases, powertransmission fluids. shock absorber fluids. and the like.

in which they are incorporated. The viscosity index im-' proving agentscan be employed in oils, greases, and power transmission fluids derivedfrom Pennsylvania crude oils, Mid-Continent crude oils asphalt baseoils. and all other types of mineral oils. as well as synthetic oils.including particularly the synthetic ester type oils. such asdi-Z-hexylelhyl sebacate and di-Z-ethylhexyl adipate, and phosphonateoils. such as dibutyt diphosphonate. tetrabutyl tetramethylencdisphosphonate, and bistZ-ethylhcxyl) Z-ethylhexyl phosphonate. Theinvention contemplates such olcaginous materials generically.

EXAMPLE 1 Separation [mm cylinder stock 0/ viscous hydrocarbons Inr usein the preparation 0/ viscosity index improving agents cylinderstock-propane solution is thereafter transferred into a chilling tankwherein the pressure is reduced to an extent requisite to volatilizesufficient propane to lower the temperature of the solution to about F.to about -50 F. Maltcup propane is added during the chilling operation.such that the ratio of propane to cylinrl-cr stock is about 3 to 1 atthe end of the chilling cycle. During the chilling cycle. petrolatum isprecipitated from the solution. The chilled cylinder stock-propanesolution containing precipitated petrolatum is transferred to a filteriecd tank and thence passed through an appropriate fitter to effectremoval of the petrolatum from the chilled solution.

Propane is added to the filtrate in an amount sutl'icient to raise thepropane-cylinder stock ratio to about ID to l and the temperature of thesolution so obtained is elevated to about I50 F. to I80 F. whereuponabout 15.000 grams of high molecular weight viscous materials areprecipitated. These viscous materials still contain some propane.

The material so obtained is then mixed at a temperature of about I F. toI F. with additional propane to increase the propane-oil ratio to about20 to l. The lempcrature of the resulting solution is lowered to about100' F. whereupon about 6.000 grams of viscous hydrocarbons areprecipitated. These materials after removal of all residual propane aredesignated as heavy resins and are characterized by a molecular weightof about i400, a viscosity of about 4100 SUS at 210' R, and a brominenumber of 3.7.

The remaining oil-propane solution is heated to about 150' F.\shcrcttr-On 9,000 grants of additional viscous hydrocarbons which aredesignated as light resins are precipitated. Any residual propane isremoved in a llash chamber. These hydrocarbons are characterized by amolecular weight of about 1300. a viscosity of about I I50 SUS at 210'F.. and a bromine number of about 4.0.

Preparation 0/ viscosity index improving agent About 9.000 grams of thevi cous materials separated from the cylinder stock. in the manner abovedescribed and designated as light resin. and L000 grams of bright stockare charged to suitable apparatus for air blowing and initially heatedto a temperature of 500 F. Air is passed through the mixture at a rateof about 60 cu. ft./ :aL/hr. as the temperature was raised. The airblowing is continued at about the same rate for approximately 8 hoursduring which time the reaction mixture is mainlaincd at a temperature ofapproximately 500' F. to produce a final product characterized by a ringand ball sot'tening point of about 250' F. The bright stock referred tois a fraction of Pennsylvania parallin base crude oil having a boilingpoint range greater than about 850 F., a viscosity of about I50 SUS at210' F. and obtained by solvent dew-axing and deresining of cylinderstock. Lubricating oil composilions containing the viscosity indeximprot'er as producer! in the manner above described The viscosity indeximprover produced by the blowing process above described is blended witha neutral oil having a viscosity of about 60 SUS at I00 F. derived fromPennsylvania paralTn base crude oil by redistillation of a wide boilingprimary distillate which has undergone chilling to remove wax. in theconcentrations and with the results indicated in Table l.

TABLI 2 Wt. I'er- V 'ls rent v'.t. \'.I improve:

EXAMPLE I I 4% by weight of the viscosity index improver described inExample I is dissolved in the commercial synthetic lubricating oil soldunder the trade name Plcxol 20L" which is essentiallydi-I-ethylhexylsebacatc. The di-2- ethylhexylscbaeate containing noviscosity index improver is characterized by a viscosity index of 154.5.The addition of 4% by weight of the viscosity index improving agents ofthis invention increase the viscosity index ot thedi-2-ethythexylsebacate to 179.7.

Similarly 4% by weight of the viscosity index improver described inExample I is dissolved in a synthetic lubrieating oil consisting ofdi-2-ethylhexyl-adipate. The di-Z- ethylhexyl-adipate containing noviscosity index improvcr is characterized by a viscosity index of lt9.3.the addition of 4% by weight of the viscosity index improving agent ofExample I increased the viscosity index of the di-Z-ethylhexyl-adipateto 183.6.

EXAMPLE Ill The procedure described with respect to TtlitlC 3 isrepeated with the exception that in this instance there is employed amedium neutral rullinate. i.c.. a solvent ex tracted n'eutral obtainedfrom Pennsylvania parallin ba e crude and having a viscosity of aboutSUS at 2H) F. and a boiling range of about 7-10 F. to about 850 F.. inlieu of the at I00 oil fraction employed in obtaining the data reportedin Table 3.

The medium neutral rallinate employed is characterized by tt pour pointof-t-IS' F. A blend of medium neutral rall'tnate with 5% by weight ofthe viscosity index improving agents of the invention is characterizedby a pour point of 20 F whereas a blend of medium neutral railinate withabout 7% by weight of the viscosity index improving agents of theinvention is characterized by a pour point of -30 F.

The procedure described with reference to Table 3 is repeated with theexception that in this instance there is employed a Pennsylvania crudeoil traction having hotling point range of about 508' to 556 F. Theresults obtained are reflected in Table 4.

TABLE 4 Wt. Per- Vis. Yis. Pour (-cut VI. at IOU at 210 V1. pointiinprover 0. l 37. 30.2 +10 4.9 42.7 32.3 I 7, (I 46. t! 4 l 187. 3 l]1010 53. 5 fi 1 8 40 EXAMPLE IV TABLE 5 Wt. Inr- Yis. Vis. cont V.I. at100 at. ill! v.1. Improver t (l [30. J 35. l 85%. T 2. Ii 67. ll 3Z7. 2104. 2 4. (l 73. .1 3T. .2 121'). 5 5. n 77. 8 37. 9 125. 7 7. U 85. 2 9137v 5 10.0 105. 5 41.8 152. 1

EXAMPLE V The process of Example I is repeated but in this instance theblowing process was stopped at a point requisite to produce a producthaving a ring and ball softening point of about 160 F. The material soformed is blended with a 60 at 100 neutral oil fraction of the typedescribed in Example I in the concentrations and with the results inimprovement in the viscosity index as reported in Tabie 6.

TABLE 6 Wt. ier- V is. i V15. 5 cent V1. at 100 at 210 V I Improver i 1O. D (it). 7 35. 1 SF. 7 2. U [57. 4 3b. 3 107. (J 4. (l 82. l) 38. 613B. 7 5. D 93. 3 40. I 143. 8 T. l] 106. 9 41. 3 H91 I 10 O 122. t] 44.4 1-56. 5

EXAMPLE VI TABLE 7 Wt. l"er Vie. ViS.

cent v.1. at IUD at 210 V.I.

Improvcr t). o 60. 7 35.1 88. 7 2. 0 67. B 36. 3 105. 7 4. 0 F5. 2 37. 5125.1 5. 0 8i]. 4 38. 4 137. 4 7r 0 88. 7 39. 5 148. 8 8. 0 99. 4 41. 4159.3

10 EXAMPLE VII The process of Example I is repeated with the exceptionthat in this instance the blowing process was stopped at a pointrequisite to produce a product having a ring and ball softening point ofabout 220 F. The material so formed is blended with a 60 at neutral oilfraction of the type described in Example I in the concentrations andwith the results in improvement in the viscosity index as reported inTable 8.

TABLE 8 Wt, Ier- Yis. Vis. (out VJ. at 100 at 210 v.1 Improve! 0. 0 60.7 l 88. T 2. t) 69. 0 313.6 115. 0 4. D 79. 0 3S. 3 138. B 7. 9 103.042. 3 164. 3

EXAMPLE VIII The process of Example I is repeated with the exceptionthat in this instance the blowing process is stopped at a pointrequisite to produce a product having a ring and ball softening point ofabout 270 F. The material so formed is blended with a 60 at 100 neutraloil fraction, of the type described in Example I, in the concentrationsand with the results in improvement in the viscosity index as reportedin Table 9.

A. The process of Example VII is repeated to produce a viscosity indeximproving agent having a ring and ball softening point of 220 F. Theproduct so obtained is then admixed with about 3 parts by weight of P 8under at atmosphere of nitrogen and heated for a period of about 2 hoursat a temperature of about 500 F. to produce an ultimate productcharacterized by a ring and ball softening point of about 250 F.

A blend of dewaxed paratfin base oil fraction derived from Pennsylvaniacrude oil and characterized by a viscosity of 1th) F. at about 60 SUS isblended with 10% by weight of the product formed in the manner abovedescribed.

The viscosity index of the original oil fraction was about 88.7 and theviscosity index of the blend was 154.2. The viscosity of the blend at100 F. was 139.3 and at 2H) F. was 46.5.

B. The procedure above described is repeated with the viscosity indeximproving agent prepared by the method of Example I, with the exceptionthat the blowing process was stopped at the time the condensationproduct is char acterized by a ring and ball softening point of about237 F. Three parts by weight of distilled P 8 is introduced into thecondensation product while at a temperature of about 240 F. Thesereactants were mixed at this temperature for about minutes to obtain anultimate product having a ring and ball softening point of about 249 F.The viscosity index improver so obtained is similar in effectiveness tothe product of Example IX-A.

C. As an alternative procedure designed to prevent decomposition of thephosphorus products, a condensation product is produced by the method ofExample I, with the exception that the blowing process is terminated toproduce a product having a ring and ball softening point of about 230 F.About 33 parts by weight of the material so obtained are blended withabout 67 parts by weight of a mixture containing 25% by volume of aneutral oil fraction separated from Pennsylvania crude oil and having aviscosity of 70 SUS at 100 F. and about 75% by volume of light neutralraffinate obtained by phenol extraction of a neutral derived fromPennsylvania crude oil and having a viscosity of 89 SUS at 100 F. To themixture so obtained, there is added 1% by weight of P S in smallproportions with nitrogen agitation. The temperature of the mixture soobtained is raised to about 225-250 F. and maintained within that rangefor a period of approximately 2 hours. The product is diluted to aconcentration of 25% by the addition of the same mixture of 70 at 100neutral and light neutral raflinate, as above described. This blendcontained about 0.54% sulfur and 0.20% phosphorus. When diluted furtherto a concentration of about 10%, this product demonstrated similareffectiveness as a viscosity index improver as the product describedunder Example IXA.

EXAMPLE X The process as described in Example IX was repeated with theexception that in this instance about 0.5% by weight of flowers ofsulfur is used in lieu of P 8 In this example the sulfur is added at thetime the ring and ball softening point of the blown product was about230. When blended in the same proportion and with the same oil as theviscosity index improver of Example IX-A, there was obtained acomposition having a viscosity at 100 F. of 148.5, at 210 F. of 48.2,and a viscosity index of 157.6.

EXAMPLE XI A viscosity index improving agent is prepared in the mannerdescribed in Example I with the exception that the blowing is terminatedat a point requisite to produce a material characterized by a ring andball softening point of about 217 F. The temperature of the product islowered in the final stages of the blowing process from about 500 F. toabout 400 F. and the blowing then discontinued. 50 grams of flowers ofsulfur is then added and the mixture agitated with nitrogen whilemaintained at a temperature of 400 F. for a period of about 2 hours toobtain a final product having a ring and ball softening point of about277 F. and a sulfur content of about 13% by Weight. This product whenblended in the proportion of about 7% by weight raised the viscosityindex of the 60 SUS at 100 F. neutral fraction described in Example 1from about 88.7 to about 161.0.

EXAMPLE XII This example is illustrative of a grease compositioncontaining a viscosity index improving agent of the type contemplated bythe invention. Approximately 88 parts of prime tallow and 85 parts ofhydrated barium hydroxide, Ba(OH) -8H O, are mixed at room temperaturein a suitable steam jacketed kettle, following which the temperature israised to above the boiling point of water to remove water ofcrystallization of the hydrated barium hydroxide and to form the bariumsoaps. In order to solubilize the barium soaps, there is added asuitable quantity of a naphthenic base stock having a viscosity of about533 SUS at 100 F., 57 SUS at 210 F. and a viscosity index of about 46.During this addition the temperature is raised to about 350 F. toinitiate gelation. Completion of the grease manufacture is effected byadding an oil mixture consisting of 10% by weight of the viscosity indeximproving agent described hereinbefore in Example I and 90% by weight ofthe 60/100 neutral fraction derived from Pennsylvania paraflinic basecrude oil described in Example I, the total mixture having a viscosityof 47.6 SUS at 210 F., 149.4 SUS at 100 F., and a viscosity index of153.3.

The resulting grease contains approximately 25% by weight of bariumsoap, about by weight of the naphthenic neutral fraction describedabove, and about 60% by weight of the high viscosity index oil mixturereferred to above, and is characterized by the following properties:

Worked penetration (ASTM D217-52T) 270 Moisture content (ASTM D12847)Percent 0.1 Dropping point (ASTM D566-42) F" 499 In addition, the greasehad good shear stability and possesses excellent pumpability propertieseven at low extremes of temperature.

EXAMPLE XIII A shock absorber fluid was compounded of the followingingredients:

Percent by weight Overhead distillate from Pennsylvania base kerosene,viscosity 30 SUS at 100 F., flash point 215 F., boiling point range 404F. to 500 F 34.4 Fuel oil-overhead distillate from coastal crude,viscosity 31.1 SUS at 100 F., flash point 230 F., boiling point range440 F. to 500 F 51.6 Viscosity index improver of Example 1 13.5Tricresyl phosphate 0.5

The shock absorber fluid so prepared was attended by the followingproperties:

Viscosity index 197.1 Viscosity at 100 F. 85.7 Viscosity at 210 F 42.2Flash point F 200 Pour point F EXAM PLE XIV 4.0% by weight of theviscosity index improver described in Example I was blended with 96% byweight of a synthetic lubricant consisting of bis (Z-ethyl hexyl) 2ethylhexyl phosphonate. The synthetic lubricant bis (2-ethyl hexyl) 2ethylhexyl phosphonate was characterized by a viscosity index of 79.0.The blend of the synthetic lubricant and the viscosity index improver ofExample I was characterized by a viscosity index of 109.4.

EXAMPLE XV A viscosity index improving agent is prepared in the mannerdescribed in Example I with the exception that the blowing process isterminated at a point requisite to provide a condensation product havinga ring and ball softening point of 180-200 F. 311.8 grams of thecondensation product so obtained are heated to a temperature of about400 F. and 0.78 gram of tolylene diisocyanate is added. The temperatureof the mixture is maintained at 400 F. with agitation for about 20minutes, during which time the reaction mixture thickened. The productso obtained is characterized by a ring and ball softening point of about245 F. This material, when blended in the proportion of about 10% byweight with the SUS at 100 F. neutral oil, described in Example I,raised the viscosity index of the oil from about 88.7 to about 163.0.

EXAMPLE XVI A viscosity index improver is prepared in the mannerdescribed in Example I with the exception that the cylinder stockdescribed in that example is used per se as the starting material fromwhich the viscosity index improver is derived.

The viscosity index improver so obtained is similar in etfectiveness tothat described in Example 1.

EXAMPLE XVII A viscosity index improving agent is prepared from afraction of Pennsylvania paraffin base crude oil designated as heavyresin described in Example I, which has been further processed bysolvent extracting with phenol to a raflinate yield.

The material above described is characterized by an average molecularweight of about 1680, a viscosity of about 1550 SUS at 210 F., a brominenumber of 1.2, and is substantially wax and asphalt free. This materialis heated to a temperature of about 475 F. and air is passedtherethrough while the reaction mixture is maintained within atemperature range of 450500 F. for a time requisite to produce a producthaving a ring and ball softening point of about 245 F.

The effectiveness of the composition so obtained as a viscosity indeximprover in the Pennsylvania oil fraction having a viscosity of 60 SUSat 100 PI, of the type previously described, is reflected in Table 10.

TABLE 10 Wt. lcr- Vis. Vis. cent V.I. at 100 at 210 VI Iinprover EXAMPLEXVIII The process of Example XVII is repeated with the exception that inthis instance there is employed in lieu of the starting materialdescribed in Example XVII a bright stock raffinate produced as followsand having the following properties: the bright stock referred to inExample I is extracted with phenol to a 92% raifinate yield and ischaracterized by a viscosity of about 140 SUS at 210 F., a brominenumber of 7.1, and a molecular weight of about 690.

The eflectiveness of this material as a viscosity index improving agentis reflected by Table 11.

TABLE 11 Wt. Per- Vis. \"is. cent v.1. at 100 at 210 V1. ImproverEXAMPLE XIX The process of Example XVII is repeated with the exceptionthat in this instance petrolatum resin is employed as a startingmaterial from which the viscosity index improving agent is formed. Thepetrolaturn resin is obtained by treating the petrolatum described in Example I with propane so that the propanezoil ratio is approximately :1and heating the resulting mixture to about 135-160" F. Petrolatum resinwhich is thereby precipitated from the solution is characterized by aviscosity of about 2800 SUS at 210 F., a gravity of about 13.6 API, anda wax content of about 40%.

The eliectiveness of the condensation product produced by blowingpetrolatum resin when employed as a viscosity index improver in the 60at 100 neutral described in Example I is reflected by Tabie 12.

TABLE 12 Wt. Per- Vis. Vis. cent. V.I. at 100 at 210 VI Iiuprovsr l 0. 06D. 7 35. 1 88. 7 5. 0 79. 7 38. 3 135. 5 it]. 0 109. 0 42. 3 152. Q 15.0 165. 0 48. 9 149. 4 20. 0 275. 7 60. 7 143. 9

EXAMPLE XX About 83.8 parts by weight of the viscosity index improvingagent produced in the manner described in Example I was heated to atemperature of about 300 F. and about 16.2 parts by weight ofphenothiazine having the following formula was incorporated into theviscosity index improving agent by a colloid rnill:

I II

The product so obtained was cooled and when blended with a base oildemonstrated marked resistance to oxidation as reflected by the resultsof a Cub Engine KRC-l7 test.

In conducting the Cub Engine KRC-17 test, there were employed twoaliquot portions of an oil containing about 94 parts by volume of amedium neutral 95% rafiinate such as described in Example III, and about0.3 part by volume of a commercial antioxidant whose es sential activeingredient is a zinc alkyl dithiophosphate in which the alkyl portion ofthe compound contains six to ten carbon atoms. To one aliquot portion ofthe above described blend, there was added about 6.8 parts by volume ofthe phenothiazine containing product of this example, whereas to theother aliquot portion of the above described blend, there was addedabout 6.4 parts by volume of the product of Exampie I. With respect tothe portion containing the phenothiazine product of this example, theCub Engine KRC-l7 test reflected a bearing weight loss of .042 mg,yielded a used oil containing about 2.9% by weight of pentaneinsolubles, and about 2% by weight of benzene insolubles. The portioncontaining 6.4 parts by volume of the product of Example I in anidentical test resulted in a bearing weight loss of 0.089 mg. and a usedoil containing about 5% by weight of pentane insolubles and about 4.8%by weight of benzene insolubles.

EXAMPLE XXI The process of Example I is repeated with the exception thatin this instance the reaction mixture is maintained at a temperature of425 F. during the blowing operation. A product having a ring and ballsoftening point of about 250 F., similar to that of the product ofExample I, is obtained after about 15 hours. The product was analogousin other respects to the product of Example I.

EXAMPLE XXII The process of Example I is repeated with the exceptionthat in this instance the reaction mixture is maintained at atemperature of 575 F. during the blowing operation. A product having aring and ball softening point of about 250 F., similar to that of theproduct of Example I, is obtained after about 5 hours. The product wasanalogous in other respects to the product of Example I.

EXAMPLE XXIII The viscosity index improving agents are prepared by theprocess of Example I with the variations of starting materials and ringand ball softening points in the final condensation products asindicated in Table 13. The effectiveness of these viscosity indeximproving agents when blended in the proportions indicated with theneutral oil having a viscosity of about 60 SUS at F., described inExample I, is reflected by the data which appears in Table 13.

15 TABLE 13 Ring and ball Percent SUS SUS Air blown materials softeningV.I.I. in at at V1.

point of Blend 100 210 V.I.I., F.

Bright stock, 83.5% rol 242 3 09. 36.9 .5 iinate (zero pour). 81. 2 38.81 6 80. 4 3i). 7 .0 7 06. 2 41. 3 1 125. 3 45. 3 .0 233. 4 57. 8 5Solvent extracted mixed 241 3 69. 1 3T. 0 0 base bright stock. 5 80.139.1 .8 (i 88. 9 40. 3 2 7 111.0 43.9 .7 10 135. i] 46. 9 .9 15 276. 701. 7 7 Light resin, 58% rafiin- 188 1 [55. 2 36. 2 .5 ate." 2 T0. 5 383 1.5 4 102. 5 43. O .13 5 122. 7 40. 3 4 228 1 04. 3 35. 9 .8 2 75. 838. 2 .9 4 103. 0 43. 3 .ti 5 124. 7 46. 8 1 270 4 102. 3 43. 3 8 Heavyresin 65% railin- 205 4 70. 8 3 .7 ate. 7 108. 2 43. 2 9 245 1. 8 71 837. 2 ii 4 87.0 30. 8 5 5 00. 3 41. 7 .7 255 2 08. 9 30. 0 I. 2 4 80. 340. 2 0 278 2 68. 8 30. 8 8 4 81. [i 30. 3 9 5 8i]. 4 40. ii 1 Heavyresin 44% rafii- 230 2 08. 3 30. 7 .13 onto (extraction 307). 6 90. 340. I3 [i 281 2 05. 0 30. 3 2 0 80. 6 40. 0 0 341 2 08. 3 30. 7 3 5 B9.0 40. 3 .0

l The bright stock, 83.5% railinate (zero pour) is derived by propanedewaxing of Pennsylvania crude residual cylinder stock followed byphenol extraction to a 83.5% raliinate yield. This stock ischaracterized by a viscosity oi140 SUS at 210 F., a molecular weight ofabout 740, and a. bromine number of about 7.0.

Solvent extracted mixed base bright stock is prepared by solventtreatment oia Mid-C ontinent basc crude residuum and is characterized bya viscosity of 152.8 SUS at 210 F., a. bromine number of 2.4, and a.molecular weight of about 770.

s The light resin 58% rall'inate is obtained by phenol extraction of thelight resins described under Example I and is characterized by amolecular weight of about 1400, a viscosity of 807.2 SUS at 210 F., anda bromine number of about 1.5.

The heavy resin 05% raihnate is prepared by phenol extraction of theheavy resin described under Example I to a 6501 raliinate yield and ischaracterized by a molecular wieght of about 1680, and bromine number ofabout 1.2, and a viscosity of about 1575 SUS at 210 F.

e The heavy resin 44% raliinate is prepared by phenol extraction of theheavy resin described under Example I and is characterized by amolecular weight of about 1570, a viscosity of about 1645 SUS at 210 R,and a bromine number of about 1.5.

EXAMPLE XXIV Lubricating oils are compounded including the viscosityindex improving agent of Example I and the viscosity index improvingagent of IX-C. In each instance, the base oil formulations contain about70.03% by weight of a light neutral raffinate and 23.3% by weight of 70at 100 neutral of the same type as described under Examplc IX-C.

To two aliquot portions of the base oil blend there is added 6.60% byweight of the viscosity index improving agent of Example I and 6.60% ofthe viscosity index improving agent first described in Example IX-C. Toa third aliquot portion of this base oil blend there is added 4.50% byweight of a polyisobutylene fraction having a molecular weight of about15,000 and 8.00% by weight of a solvent extracted neutral derived fromMid-Continent base crude and having a viscosity of about 160 SUS at 100F. The compounded oils so obtained had equivalcnt viscositics at 210 F.and were subjected to Underwood oxidation tcsts with the followingresults after hours test time.

The Underwood oxidation test is carried out as described by H. C. Mougcyin a preprint of World Automotive Engineering Congress, SAE, New Yorkcity (May 1939) with the exception that the test time is extended toabout 20 to 25 hours.

EXAMPLE XXV Automatic transmission fluids were compounded from theproducts of Examples I, IX-A, X and XV, as follows:

TABLE 15.COMPOUNDING i)ATA AU'IOMYIIC TRANSMISSION FLUID FORMULATIONS'Dewaxerl 60,000 Neutral, perccnti 41. 43 500 at 100 Napbtheuic Neutrahe The dcwaxcd 60000 neutral is the same type of neutral derived fromPennsylvania base crude described under Example I but which has h -cnfurther dewaxcd to a pour point of 35 F.

The 500 at 100 naphthcnic neutral is a straight distillate ohtainml froma naphthcnic base crude and is characterized by a :osity of 57.0 SUS at210 F. and 530 SUS at 100 F. and a pour point of 30 i a A commercialproduct sold as Lubrizol LZ JBZ containing an anti- [omn agent, a mildcxtrelnc pressure agent, and an antioxidant.

d The pour point depressant is an oil solution of a polymeric.methacrylic ester having a viscosity of about 3000 5 S at 210 I".

The commercial viscosity index improver is an oil solution containing apolymeric methacrylio ester and having a viscosity of about 4000 SUS at210 1*.

These materials were subjected to the Underwood oxidation test with theresults after 25 hours reflected in Table 16.

TABLE 10 Product of Example+ Commercial improver EXAMPLE XXVI There iscompounded a hydramatic transmission fluid from the followingingredients:

61.1% by weight of double dewaxcd at neutral of the type described infootnote 3 of Table 15.

24.8% by weight 500 at 100 naphthenic neutral.

0.5% of zinc alkyl dithiophosphatc additive in which the alkyl groupsare derived from aliphatic alcohols containing 6 to 10 carbon atoms andsold as Lubrizol L2- 360.

6.65% of a commercial oil additive sold as Lubrizol LZ- 282 andcontaining an antifoam agent, a mild extreme pressure agent, and anantioxidant.

6.82% of the viscosity index improver of Example I.

0.1% of the pour point depressant described in footnote of Table 15.

T110500 at 100 naplithenie neutral referred to is a straight distillatederived from a naphthenic base crude anll s churai'terizeil by :1viscosity of 57.6 SUS at 100 F. and will hi 3 at 210 I and a pour pointof -30 F.

1 7 The results obtained from testing this fluid in the hydrarnatictransmission of a 1953 Oldsmobile are as follows:

EXAMPLE XXVII Approximately 5670 grams of 90% light resin, as describedin Example I, is blended with 10% bright stock raflinate, as describedin footnote 8 of Table 13, and is air blown at a temperature of about500 F. to a ring and ball softening point of about 200 F. This productis lowered to a temperature of 430 F. at which time about 383.5 grams ofelemental sulfur are added. After a reaction time of about four hours,the ring and ball softening point of the product rises to about 290 F.and the product contains about 1.63% sulfur. To about 5200 grams of thisproduct, there is added 244 grams of diphenylamine while the reactionmixture is held at a temperature of about 400450 F. for two hours. Thereis produced in this manner a final product having a ring and ballsoftening point of 293 F.

About 7.5% by weight of this product is blended with 92.5% by weight ofa 70/100 light neutral raflinate of the type described and the resultingoil is tested by the Underwood oxidation test procedure. The Underwoodoxidation test results, after 20 hours test time, are as follows:

Bearing weight loss mg 5.7 Sludge, naphtha insolubles trig/10 gm. oil16.3 Viscosity increase percent -5.0

EXAMPLE XXVIIl 3860 grams of the same mixture of light resin and brightstock rafiinate, as described in Example XXVII, air airblown at atemperature of about 500 F. to a ring and ball softening point of about190 F. At this point, there is added 10% by weight of a mixture ofpolyalkylene polyamines consisting predominantly of diethylene triamineand triethylene tetramine. The temperature of the reaction mixture ismaintained at 400 F. for a period of two hours, following which theproduct is stripped of volatile light ends by bubbling nitrogenvigorously therethrough. The product so produced is further blended withabout 0.3% by weight of a zinc dithiophosphate of e the type describedin Example XXVI. This material was tested by the Cub Engine KRC-19 testprocedure with the following results:

Piston color 6.6 Bearing weight loss grams .05 Viscosity increasepercent 140 Pentane insolubles percent by weight .79 Benzene insolubles-do .66

EXAMPLE XXIX 400 grams of the viscosity index improver of Example I aremixed with 66.8 grams of ,B-naphthylphenylaminc with agitation and at atemperature of about 450 F. When the amine is completely dispersed,there is added 4633.2 grams of a medium neutral rafiinate, such asdescribed in Example 111, and 17.5 grams of a zinc dithiophosphate ofthe type described in Example XXVI. The resulting composition is testedby the Cub Engine KRC- 19 test procedure with the following results:

Piston color 6.0 Bearing Weight loss "grams" .032 Viscosity increasepercent 38 Benzene insolubles do 0.31 Pentane insolubles do 0.35

18 EXAMPLE xxx About 100 parts by weight of a heavy neutral raflinate isheated to a temperature of about 450 F. and airblown to a ring and ballsoftening point of about 250 F. The product so obtained is mixed in aconcentration of about 4% by weight with the synthetic oildi-Z-ethylhexyl adipate. The viscosity index of the di-2-ethylhexylad-ipate alone is 119.3. The viscosity index of the mixture ofdiQcthylhcxyl adipate and the viscosity index improving agent of thisexample in a concentration of 4% by weight is 144.4.

The heavy neutral ralfinate employed is a neutral oil product derivedfrom Pennsylvania crude oil as an overhead distillate. The overheaddistillate is dewaxed by propane and solvent refined with phenol toproduce a final raffinate product characterized by hydrocarbons havingan average ebullioscopic molecular weight of about 500.

EXAMPLE XXXI Example XXX is repeated with the exception that in thisinstance di-Zethylhexyl sebacate is employed as the base synthetic oilto which the viscosity index improving agent produced in the mannerdescribed in Example I is added. The viscosity index of thedi-Z-ethylhexyl sebacate alone is 154.5. The viscosity index of themixture of di-2-ethylhexyl scbacate with 4% by weight of the viscosityindex improver is 180.2.

EXAMPLE XXXII About 100 parts by weight of a Pennsylvania bright stockextract which is a fraction of Pennsylvania crude oil removed fromPennsylvania bright stock by phenol extraction was employed as astarting material for the production of a viscosity index improver. Thisbright stock extract is characterized by the following physicalcharacteristics:

Gravity, A1 1 10.4 Viscosity at 100 F., SUS 840,000 Vsicosity at 210 F,SUS 12.10 Viscosity index -173 The bright stock extract is blown at atemperature of about 450 F. with air to produce a final product having aring and ball softening point of about 250 F. Di-Z- ethylhexyl sebacate,a synthetic oil characterized by a viscosity index of 154.5, was blendedwith 4% by weight of the blown bright stock extract product. The mixtureso produced was characterized by a viscosity index of 167.6.

EXAMPLE XXXIH The process of Example I is repeated with the exceptionthat the blowing process is stopped at a point requisite to produce aproduct having a ring and ball softening point of about 120 F. Theproduct so produced is then treated at a temperature of 500 F. with 1%by weight thereof of phosphorus pentasulfide added in four 1 1%increments, one increment every fifteen minutes. The phosphorouspentasulfidemodified product so produced is characterized by a ring andball softening point of 184 F. This product is further treated at 500 F.with about 3 s% by weight, based on the original blown product prior totreatment with phosphorus pentasulfide, of elemental sulfur added insmall increments over a period of approximately five hours to produce afinal product characterized by a ring and ball softening point of 242 F.and containing 0.19% by weight phosphorus and 1.34% by weight sulfur.This product when blended with a Pennsylvania 60 at 100 neutral in aconcentration of 4% by weight gives a product having a viscosity at 100F. of 69.8 SUS, a viscosity at 210 F. of 37.1 SUS, and a viscosity indexof 136.7.

EXAMPLE XXXIV 1 /2 parts by weight of barium nonyl phenate containing18.03% by weight of barium is blended with one part by weight of amedium neutral raffinate of the type described in Example III, togetherwith one part of water for each 12 /2 parts of phenate to provide a morecompatible mixture. The blend so produced is added in six increments toa mixture of one part by Weight of the viscosity index improverdescribed in Example I, and four parts by weight of the same mediumneutral rallinate. The mixing is effected at a temperature of 220 C.Subsequent to the addition of each increment, the mixture is stirred for30 minutes and blown with carbon dioxide for an additional 30 minutes,with the exception of the final increment, the addition of which isfollowed by a 30 minute stirring period and a 60 minute period ofblowing with carbon dioxide.

The exhaust gas, which carries nonyl phenol, is passed through acondenser in a benzene scrubber. 65.7% by weight of the nonyl phenol isrecovered.

The finally produced blend is centrifuged and filtered and contains3.12% barium. This blend is diluted with the same medium neutralraffinate to a concentration of 8 /3 by weight thereof in saidrallinate. At this dilution, the viscosity of the mixture at 100 F. is394.5 SUS, the viscosity at 210 F. is 62.5 SUS, and the viscosity indexis 108.4. A comparative mixture containing by weight of the viscosityindex improver of Example I and 90% by weight of the medium neutralraffinate is characterized by a viscosity at 100 F. of 413.0 SUS, aviscosity at 210 F. of 66.5 SUS, and a viscosity index of 125.8.

The KRC-17 engine test referred to in Example XX is a test procedure runin a Cub engine, which procedure is designed to coordinate with the CRCL4 test. Specifically, the conditions observed in the KRC-l7 testentailed operation of the engine at 2500 rpm. at 11 brake horsepower for40 hours, with an oil temperature of 265 F. and a Water jacket outlettemperature of 200 F.

The KRC-l9 engine test referred to in Example XXVIII is analogous to theKRC-17 test with the exception that a jacket outlet temperature of 250F. is maintained.

The condensation products which constitute the viscosity index improvingagents of this invention are somewhat heterogeneous in character. It ispostulated that such compositions, at least in substantial part, partakeof a microgel structure which is responsible for the remarkableeffectiveness of the compositions as viscosity index improving agents.

The term microgel denotes resins condensed to super polymeric size, eachsuperpolymer molecule being essentially a small particle of condensateof colloidal dimensions. The formation of microgel may occur in situduring reaction due to the heterogeneity of the oxygen condensing agentemployed with the charge stocks (e.g., butadiene polymerization inemulsion produces microgels of size approximately that of the startinglatex particles, W. V. Baker, Ind. & Eng. Chem., 41, 511-520, 1949) ordue to subdivision of macrogels to submacrogels of microgel size throughmechanical or thermal means, or due to some obscure means.

It is noted that initially both the intrinsic viscosity and the ring andball softening point of the viscosity index improving agents of theinvention increase with the time of the blowing or condensationreaction. However, after a blowing or condensation time period, forexample, of. about five hours, the intrinsic viscosity values remainessentially constant for an additional time interval and then slightlydecrease, whereas the ring and ball softening point values continue toprogressively increase as the condensation proceeds. As previously foundby Baker and others (Morton, Ind. & Eng. Chem. 47, 333) in studies ofinherent viscosity (a measure of intrinsic viscosity) against percentconversion of diene emulsion polymerizations, the inherent viscositiestend to pass through a maximum when microgel formation occurs. While thepercentage of conversion cannot be specified with respect to theviscosity index improving agents of the invention, it is evident thatcondensation proceeds throughout the duration of the reaction steadilyinasmuch as the ring and ball softening point values progressivelyincrease with reaction time.

The phenomenon of constant or maximal intrinsic viscosity values withtime of reaction has been attributed in diene emulsion polymerization(Baker, loc. cit.) to a change in molecular structure, i.e., formationof microgels. The microgel as with other gelations incorporates thelongest chains, leaving a decreased weight average molecular weightcomponent in the sol residue. The observations of the present workappear to be immediately analogous to the emulsion polymerizationstudies involving microgel formation reported above.

We claim:

1. A hydrocarbonaceous condensation product having a combined oxygencontent not in excess of about 5% by weight, said product being producedby contacting a petroleum fraction starting material in which thehydrocarbons present have an average ebullioscopic molecular weight inexcess of about 500, while at a temperature of at least about 400 F.,with a free oxygen-containing gas, and thereafter reacting thecondensate so produced with a material selected from the groupconsisting of elemental sulfur and the phosphorus sulfides.

2. The condensation product of claim 1 wherein the material employed forreacting with the condensate is elemental sulfur.

References Cited by the Examiner UNITED STATES PATENTS 2,279,294 4/1942Hardrnan 260563 2,297,531 9/1942 Bock 260-563 2,427,272 9/1947 Fuller eta1 252- XR 2,483,571 10/1949 Brennan et al. 260399 2,611,782 9/1952Bortnik 260453 2,689,891 9/1954 Thompson 260453 2,744,872 5/1956 Nelson25255 XR 2,753,307 7/1956 Foehr et a1. 25255 XR 2,853,480 9/1958 Lindert260l39 2,935,505 5/1960 Lacoste et al 260139 CHARLES B. PARKER, PrimaryExaminer.

DANIEL D. HORWITZ, JOSEPH P. BRUST,

Examiners.

DELBERT R. PHILLIPS, Assistant Examiner.

1. A HYDROCARBONACEOUS CONDENSATION PRODUCT HAVING A COMBINED OXYGEN CONTENT NOT IN EXCESS OF ABOUT 5% BY WEIGHT, SAID PRODUCT BEING PRODUCED BY CONTACTING A PETROLEUM FRACTION STARTING MATERIAL IN WHICH THE HYDROCARBONS PRESENT HAVE AN AVERAGE EBULLIOSCOPIC MOLECULAR WEIGHT IN EXCESS OF ABOUT 500, WHILE AT A TEMPERATURE OF AT LEAST ABOUT 400*F., WITH A FREE OXYGEN-CONTAINING GAS, AND THEREAFTER REACTING THE CONDENSATE SO PRODUCED WITH A MATERIAL SELECTED FROM THE GROUP CONSISTING OF ELEMENTAL SULFUR AND THE PHOSPHORUS SULFIDES. 